Glaciers in Greenland are changing rapidly. To better understand these changes, we have produced a series of seven synthetic aperture radar (SAR) backscatter mosaics for seven winters during the period from 2000 to 2013. Six of the mosaics were created using RADARSAT Fine-Beam data and the seventh used ALOS-PALSAR Fine-Beam Single-Polarization data. The RADARSAT mosaics are radiometrically calibrated and capture changes in the backscatter coefficient related to melt and other events, particularly the strong melting in the summer of 2012. Comparison of features in the ascending-orbit ALOS mosaic and the descending-orbit RADARSAT mosaics indicate that in areas of smooth to moderate topography their locations are consistent to within a few tens of meters. The locations of features identifiable in the RADARSAT mosaics, which were collected with the same imaging parameters, generally agree to within better than the 20 m posting of the data. With such geometric accuracy, these data establish a record of change in Greenland for the early part of the 21st century, thus providing a baseline that can be compared with new radar and optical datasets.

中文翻译：

---

格陵兰岛 21 世纪初变化的 SAR 记录

格陵兰的冰川正在迅速变化。为了更好地理解这些变化，我们为 2000 年至 2013 年期间的七个冬天制作了一系列七个合成孔径雷达 (SAR) 反向散射马赛克。其中六个马赛克是使用 RADARSAT 细光束数据创建的，第七个使用 ALOS- PALSAR 细光束单偏振数据。RADARSAT 镶嵌经过辐射校准，并捕捉到与融化和其他事件相关的后向散射系数的变化，特别是 2012 年夏季的强融化。上升轨道 ALOS 镶嵌和下降轨道 RADARSAT 镶嵌特征的比较表明，在地形平坦到中等的区域，它们的位置一致，在几十米以内。在 RADARSAT 马赛克中可识别的特征的位置，使用相同的成像参数收集的数据通常优于 20 m 发布的数据。凭借如此精确的几何精度，这些数据建立了 21 世纪早期格陵兰变化的记录，从而提供了可以与新的雷达和光学数据集进行比较的基线。